The present invention relates to a coaxial cable shielding terminal electrically connected to a braided shield exposed at a terminal end of a coaxial cable.
Generally, in order to shield a coaxial cable used as an antenna wire or the like from electrical noises, such as electromagnetic waves and static electricity, the coaxial cable is constructed such that a conductor core covered with an insulating cladding, that the insulating cladding is covered with a braided shield, and that the braided shield is covered with an insulating sheath. Further, various coaxial connectors for connecting such a coaxial cable to a mating device or a mating connector have been proposed. Furthermore, such a coaxial connector uses a coaxial cable shielding terminal for the ground connection of the braided shield of the coaxial cable to an appropriate grounding portion. FIG. 8 illustrates an example of such a coaxial cable shielding terminal (see, e.g., Patent Document 1).
A coaxial cable 133 illustrated in FIG. 8 is constructed as follows. That is, an end portion of each of an insulating sheath 139, a braided shield 135, and an insulating cladding 138 is peeled off such that the braided shield 135, the insulating cladding 138, and a conductor core 137 are exposed by a predetermined length. Then, an inner terminal 141 for the fitting-connection of the conductor core 137 to a mating connector is attached to the conductor core 137.
The coaxial cable shielding terminal 131 illustrated in FIG. 8 is obtained by performing press-working on one metal sheet. The coaxial cable shielding terminal 131 has a cylindrical terminal body 143 that accommodates an inner terminal 141 of the coaxial cable 133 on the central axis thereof, a terminal bottom plate portion 144 extending from one end of the terminal body 143, a pair of press-clamping pieces 151 that are respectively erected from both side edges of the terminal bottom plate portion 144 and that press-clamp the braided shield 135, a pair of crimping pieces 153 that are erected from both side edges of the terminal bottom plate portion 144 and that crimp the insulating sheath 139, and an insertion piece 155 which extends from one end of the terminal body 143 to face the terminal bottom plate portion 144 and is cross-sectionally shaped like a circular arc plate extending along the inner circumferential surface of the braided shield 135, and which is inserted into between the insulating cladding 138 and the braided shield 135.
The coaxial cable shielding terminal 131 of the configuration crimps the press-clamping piece 151 onto the braided shield 135 in a state in which the insertion piece 155 is inserted from the terminal end side of the coaxial cable 133 into between the insulating cladding 138 and the braided shield 135. Thus, the coaxial cable shielding terminal 131 sandwiches a part of the braided shield 135 between the insertion piece 155 and a distal end of the press-clamping piece 151. Consequently, the braided shield 135 and the coaxial cable shielding terminal 131 are electrically connected to each other. Further, the coaxial cable shielding terminal 131 is electrically connected to an appropriate grounding portion. Thus, the braided shield 135 is earth-connected to the grounding portion.
[Patent Document 1] JP-A-2004-319175
However, the conventional coaxial cable shielding terminal 131 has a problem in that the holding force of the press-clamping piece 151, which is applied to the braided shield 135, is low, so that the braided shield 135 press-clamped to the press-clamping piece 151 is displaced, and that the braided shield 135 slips off between the press-clamping piece 151 and the insertion piece 155.
In order to address this problem, a crimping load at the press-clamping of the braided shield 135 by crimping the press-clamping piece 151 is increased. Thus, the holding force applied to the braided shield 135 can be increased. However, this brings in a new problem that the conductor core 137 is pressed, so that the conductor core 137 may be broken or deformed. Thus, it is easy to increase the holding force of the press-clamping piece 151, which is exerted onto the braided shield 135, by maintaining good high-frequency characteristics of the coaxial cable 133.